"an hour and a half" or "one and a half hours"

Solution 1:

Both of these are equally good with hours and other common measurements. But maybe not with less common measurements. For example:

He drank one and a half glasses of water.

is more common than

He drank a glass and a half of water.

The are both correct, and interchangeable; assuming you mean 90 minutes. One and an indicate the same singular quantity.

It seems that one is more likely to be used by certain people and not others. In the UK, sentences like

"The Superbowl (or anything else) starts in less than an hour and a half."

are more common and natural.